Stoking mechanism



May 5, 1942- w. T. HANNA STOKING MECHNISM Filed Jan.

JNVENTOR. WL'llL'am T Hanna,

ZM .4 TTU EYS BY Qian-,Q

Patented May 5, 1942 UNITED STATES PATENT OFFICE 2,281,765 sToKrNG MECHANISM William Thompson Hanna, Cincinnati, Ohio Application January 27, 1938, l.Serial No. 187,150 s claims. (o1. 11o-101) trated in the drawing accompanying the present specification and in which- Figure 1 is a central longitudinal vertical section of a portion of a stoking device applied to a locomotive rebox;

Figure 2, an oblique section on the line 2--2 of Figure l;

Figures 3 and 4, fragmentary detail views illustrating a ball and undercut slot connection between the deflectors and their respective operating devices, and

Figure 5 is a section taken on line 5--5 of Figure 1.

As shown in the drawing, a cylindrical coal feeding conduit I located above deck D of a locomotive is provided with a screw conveyor having a hub 2 journaled at 3 and driven by a shaft 4 through a suitable coupling, as a universal joint indicated at 5. Shaft 4 may be driven by suitable power distributing device generally indicated at da. Coal is fed to conduit I from an elevating conduit 6 through a delivery port 1, Figure 2, in the bottom wall of conduit I. A cover 8, preferably hinged, covers an opening in the top wall of conduit I giving access to the interior thereof. A hinged cover 9, Figure 1, covers an opening in conduit 6, giving access to the interior thereof. A toggle comprising a link 9a and pivoted lever 9b provided with operating handle 9c (shown in dotted lines) is provided to conveniently open and close door cover 9. The coal is fed to conduit 6 from a transfer conduit I0 below the deck D and provided with a screw conveyor Ia.

The delivery end of conduit I opens into a chamber Ia wherein coal mass fed thereto from conduit I is brought to a suitable loose and mobile condition and in which chamber the passage of the fuel to distributing apparatus generally indicated at |00 is controlled. The chamber Ia is part of a housing generally indicated at IUI, which encircles and encloses the firing opening II in the back head I2 of the locomotive. The housing IIII has a hand-firing opening |02 normally closed by a fire door, not shown. Referring to Figure 1, 2 and 5, the chamber is located in the lower portion of the housing and comprises an upwardly, forwardly sloping bottom wall I4 having a central fiat fuel supporting surface IS and side conically shaped fuel supporting surfaces I'I and I8 which drop away from the surface I6 as shown in Figures 1 and 2. The surface I6 narrows towards its uppermost end and the surfaces I 1 and I8 widen toward the upper ends. These three surfaces terminate in a horizontal ledge I9. n

The sides of the chamber are formed by verticalmdiverging walls I5 and I5a which extend into the side walls of the housing IOI. The top wall of the chamber is substantially horizontal and is not as long as the bottom wall I4 so that the two walls I3 and I4 and the sidewalls MI5 and 4I5@ form a chamber which widens toward its delivery openings and which has a portion thereof restricted by the top wall I3 for a portion thereof. v g

Referring to Figure 1, located` immediately in front of the ledge I9 is a combined blast chamber and fuel screening device generally indicated `at 30 and which is partA of the fuel distributing mechanism |00.I This,V device is shown and described in greater` detail in my United States PatentNo. 2,090,628, and comprises generally a plurality, of diverging ngers having diverging openings therebetween and fuel supporting surfaces on the top thereof which slope downwardly and forwardly. A blast of steam is emitted from -the end of each finger supplied through a suitable source as describedin the said patent. Below and rearward `of the ends of the fingers is an elongated slot from which is emitted a sheet blast of steam as described in the patent in ythe form of a jet.r These two types of steam jets sweep over a fuel distributing plate generally indicated at |03 also described in said patent. This fuel distributing mechanism is designed to distribute fuel fed thereto `uniformly over the rebed as desired. Thus fuel reaching the top of the blast chamber and fingers in a loose condition runs down over the lingers and is screened so that the larger particles of fuel ride over the top of the fingers and are carried olf by the jets from the fingers themselves, whereas the nger fuel drops between the fingers and is carried off by the sheet jet which generally is emitted with less `force than the' jetsfrom vthe fingers.

Deflector plates 20 and 26 are provided on either side of the chamber Ia for guiding the flow of fuel therethrough to the fuel distributing apparatus. The deflector plate 20 is pivotally mounted as on a pintle 2I arranged in the casing with its longitudinal axis inclined to its bottom edge, Figure 1, in such manner that said bottom edge of deiiector 2U wipes across the slightly curved or conical surface I1 when said dei-lector is swung on said pintle. For this purpose and also to hold deflector 2d in any desired position of angular adjustment, said deiiector has a lug 22, Figures 3 and 4, provided with an undercut slot 23 which receives a ball 2li forming the end of a threaded adjusting bolt 25. It will be obvious that by proper manipulation of bolt 25 deector 20 may be adjusted to and held anywhere between retracted position, indicated in full lines, and extended position, indicated in Cil dotted lines in Figure 2. In like manner, the de-u o flector 26 on a pintle 27 may be mounted and actuated in relation to the inclined curved surface I8. In effect, the defiectors and 26 cooperate with other herein described devices to control the distribution or direction of delivery of coal fed to the conditioning chamber from the conduit I by the screwA conveyor therein.

As shown more clearly in Figure 1, the deflectors extend from the delivery end of conduit I through the conditioning chamber and outwardly beyond the delivery opening of said chamber, forming in effect a trough-like passageway of adjustable depth and width at its outer end. The variation in depth occurs with adjustments of the deectors in relation to the surfaces I1 and I8 which are inclined away from the plane of central surface It. Thus When the deflectors are in extended (dotted line) position, the coal discharge passageway between them is narrower than when they are in retracted or any intermediate position. This arrangement enf' ables the operator to vary the amount of coal delivered to different areas or zones of the firebox at will while maintaining a substantially constant rate of coal fed to the fire as a whole.

To obtain the most enicient operation of distributing mechanism IIIl the fuel reaching it, as above pointed out, should be loose so that the screening effect of the fingers is obtained. Also, the fiow of fuel to the distributing mechanism should be regulated and substantially uniform so that the fuel handling capacity of the distributing mechanism is never exceeded. To this end the hub 2 carries a helical screw having a hubless conditioning forward vane portion 28 extending beyond the delivery ends of the conveyor vane portion 29 and hub 2. The conveyor vane 29 is preferably of uniform diameter and pitch, whereas the hubless vane portion 28 tapers toward its forward end and is of progressively diminishing pitch. As shown in the drawing, the taper of hubless vane 28 conforms approximately to the inclination or convergence angle of the bottom wall and the short top wall of the conditioning chamber and of the deflectors 20 and 26 when in the extended position represented in dotted lines, Figure 2.

In operation the coal is fed by the conveyor Illa from below the locomotive cab deck up through the conduit 6 into the conduit I. There it is forced by conveyor 29 forwardly through the chamber over the ledge I9 to the distributing mechanism IDI). The fuel coming in contact with the rotating hubless vane 28 with its decreasing pitch and taper and so with its materially decreased fuel handling capacity is thinned or disrupted or generally caused to move sideways and forwardly and to spread out. Thus it is caused to move over the ledge I9 in a regulated stream in a condition thinner than the fuel emerging from the conduit 6.

As above described, the direction of the main flow of the fuel and/or the concentration of the stream of fuel, i. e., the depth of the stream may be controlled by the deflectors thus to concentrate the delivery of the fuel where desired. But under no circumstance is the fuel flow stopped by the conditioning or deflecting mechanism. The short top wall I3 permits the fuel to boil up in the event the supply is increased when the deiiectors are in their converging position.

To concentrate delivery of fuel in the central longitudinal zone of the rebox, both defiectors are brought to extended (dotted line) position, thus affording a narrower discharge passageway. For distribution of the fuel more thinly over a wider central area, the deflectors are both retracted to widen the passageway the necessary amount. If a greater supply of fuel is needed at one side of the central rebox Zone, one deiector will be extended and other retracted toward said side.

As various embodiments might be made in the construction herein described, all without departing from the scope of the invention as dened in the appended claims, it is to be understood that all matter herein set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. Stoker mechanism adapted to be mounted on the back head of a locomotive flrebox and comprising a cylindrical feed. conduit, a condi- Ationing chamber connected thereto and having lateral Wall portions diverging and top and bottom wall portions converging to form at their outer edges a laterally extended and vertically restricted discharge opening, said bottom wall portion 4being formed to present interiorly a centrally disposed coal supporting surface and a laterally disposed coal supporting surface at each side thereof and inclined at an angle thereto, a deflector plate mounted for swinging movement across each of said laterally disposed inclined coal supporting surfaces to adjustably define a passageway for coal to be discharged through said opening, means for actuating said plates, and a screw conveyor operatively mounted to rotate in said conduit and having a helical vane of which a conveyor portion extends lengthwise through said conduit and a coal conditioning portion extends into said passageway between said plates.

2. Stoker mechanism adapted to be mounted on the back head of a locomotive rebox and comprising a cylindrical feed-conduit, a conditioning chamber connected thereto and having lateral wall portions diverging and top and bottom wall portions converging to form at their outer edges a laterally extended and vertically restricted discharge opening, said bottom wall portion being formed to present interiorly a centrally disposed coal supporting surface and a laterally disposed coal supporting surface at each side thereof and inclined at an angle thereto, a deflector plate mounted for swinging movement across each of said laterally disposed inclined coal supporting surfaces to adjustably define a passageway for coal to be discharged through said opening, means for actuating said plates,

and a screw conveyor having a helical Vane of which a uniformly pitched conveyor portion is mounted on a hub in said cylindrical conduit and va tapering conditioning portion of progressively diminishing pitch extends beyond said hub into said conditioning chamber and cooperates with a portion of the top thereof and with a portion of said `centrally disposed coal supporting surface to condition coal for delivery through said discharge opening.

3. In a locomotive Stoker, the combination, with a firebox having a firing opening, of a fuel supply conduit terminating in a fuel conditioning chamber having a delivery ledge extending across said firing opening and over which fuel flows to said firing opening, fuel distributing means forward of said delivery ledge for distributing the fuel over said firebox, screw conveyor means in said supply conduit, a, tapered worm provided in said conditioning chamber driven from the forward end of said screw conveyor and acting to thin and condition the fuel as it moves through said conditioning chamber and acting further to regulate the fuel flow over said delivery ledge, the bottom wall of said fuel conditioning chamber comprising a central portion sloping forwardly and upwardly to said delivery ledge and side portions dropping away from the central portion and also sloping forwardly and upwardly to said delivery ledge, and defiectors for controlling the spreading movement of the fuel in the conditioning chamber and for directing the flow over one end or the other of the delivery ledge or over the central portion thereof.

4. In a, locomotive stolzer, the combination with a fire box having a firing opening of a fuel supply conduit terminating in a fuel conditioning chamber having a delivery ledge extending across said firing opening and over which fuel flows to said firing opening, fuel distributing means forward of said delivery ledge for distributing the fuel over the said fire box, screw conveyor means in said supply conduit, a tapered worm provided in said conditioning chamber driven from the forward end of said screw conveyor and acting to thin and condition the fuel as it moves through said conditioning chamber and acting further to regulate the fuel flow over said delivery ledge, the bottom wall of said conditioning chamber sloping forwardly and upwardly at an angle appreciably greater than that of the corresponding wall of said supply conduit and reaching to said delivery ledge, said bottom wall comprising a central raised portion and side portions dropping away from the central portion, and means effectively providing side walls for said conditioning chamber adjustable with respect to the vertical for controlling the spreading and conditioning movement of the fuel in the conditioning chamber and for controlling the flow over the delivery ledge.

5. In a locomotive stoker, the combination with a fire box having a firing opening of a fuel supply conduit terminating in a fuel conditioning chamber having a delivery ledge extending across said firing opening and over which fuel flows to said firing opening, fuel distributing means forward of said delivery ledge for distributing the fuel over the said re box, screw conveyor means in said supply conduit, a tapered hubless worm provided in said conditioning chamber driven from the forward end of said screw conveyor and acting to thin and condition the fuel as it moves through said conditioning chamber and acting further to lregulate the fuel flow over said delivery ledge, the bottom wall of said conditioning chamber sloping forwardly and upwardly at an angle appreciably greater than that of the corresponding wall `of said supply conduit and reaching to said delivery ledge, said bottom wall comprising a central raised portion and side portions dropping away from the central portion, and means effectively providing side walls for said conditioning chamber adjustable with respect to the vertical for controlling the spreading and conditioning movement of the fuel in the conditioning chamber and for controlling the iiowl over the delivery ledge.

6. In a locomotive stoker, the combination with a fire box having a firing opening of a fuel supply conduit terminating in a fuel conditioning chamber having a delivery ledge extending across said ring opening and over which fuel flows to said firing opening, fuel distributing means forward of said delivery ledge for distributing the fuel over the said fire box, screw conveyor means in said supply conduit, a tapered worm provided in said conditioning chamber driven from the forward end of said screw conveyor and acting to thin and condition the fuel as it moves through said conditioning chamber and acting further to regulate the fuel flow over said delivery ledge, the bottom wall of said conditioning chamber sloping forwardly and upwardly at an angle appreciably greater than that of the corresponding wall of said supply conduit and reaching to said delivery ledge, and a top wall converging forwardly toward said bottom wall, and the fuel guiding surface of the central portion of said bottom wall being raised with respect to the side portions, which side portions drop away from the central portion thereof, and means effectively providing diverging side walls for said conditioning chamber adjustable with respect to the vertical for controlling the spreading movement of the coal in the conditioning chamber and for controlling the iiow over the delivery ledge.

'7. In a locomotive stoker for supplying fuel to a firebox through a firing opening in a back wall thereof, the combination comprising, a fuel supply conduit terminating in a fuel-conditioning chamber having a, delivery ledge extending across said firing opening and over which fuel flows to said firing opening, screw conveyor means in said supply conduit, fuel-moving means in said conditioning chamber, the bottom wall of said conditioning chamber sloping forwardly and upwardly and at an angle appreciably greater than that of the corresponding wall of the supply conduit and reaching to the delivery ledge, a top wall converging forwardly toward said bottom wall, and the fuel-guiding surface of the central portion of said bottom wall being raised with respect to the side portions thereof, which side portions drop away from the central portions thereof, said raised portion being adapted to cause the spreading of the coal in said conditioning chamber and to increase the concentration of the flow of the coal passing therethrough over the side portions of said delivery ledge, and means effectively providing diverging side walls for said conditioning chamber adjustable with respect to the vertical for controlling the spreading movement of the coal in the conditioning chamber and for controlling the flow over the delivery ledge.

8. Stoker mechanism adapted for delivering coal into the firing opening of a locomotive frebox and comprising a forwardly and upwardly extending conduit communicating with the firing opening, said conduit having a cylindric conveying section spaced from the backhead and a fuelconditioning section disposed intermediate said conveying section and said firing opening, said fuel-conditioning section being provided with top and bottom walls converging on a common axis and side Walls relatively diverging, a screw conveyor Within said conduit, said conveyor comprising a helical vane having a portion which is of constantl diameter and disposed Within said conveyor section to feed fuel into said conditioning section, and another portion which is tapered and disposed Within and extending forward from the rear of said fuel-conditioning section, said latter portion being formed so that the taper thereof coincides substantially with the said convergence of said top and bottom Walls to cause the coal to spread out laterally in said conditioning section, and means effectively providing side Walls for said conditioning chamber extending from the rear thereof and adjustable with respect to the vertical for controlling the spreading and conditioning movement of the fuel in the conditioning chamber and for controlling the flow from the fuelconditioning section.

WILLIAM THOMPSON HANNA. 

